Intro to annelida

2. Intro to annelida

3. Leech Anatomy

4. Leeches in medicine

5. Annelida Review: Write the questions & use the book & your notes to answer the questions.STUDY ALL NOTES/HANDOUTS/PICTURE…this review does not cover EVERYTHING~~ 1. Identify 2 factors used as the basis for dividing annelids into 3 classes. 2. List the advantages of segmentation. 3. How does an earthworm exchange oxygen and carbon dioxide with its environment? 4. What is metamerism? Identify 3 reasons why it is advantageous? (textbook) pg. 211 5. What is tagmatization? (textbook) 6. Identify the 3 classes of Annelids and give an example of each. 7. Use a flow chart (arrows) to trace the involvement of setae and muscle contractions as an earthworm moves. 8. Use a flow chart to trace the feeding and digestion process of earthworms. 9. What 2 structures do leeches lack? 10. How are leeches used medicinally following surgical procedures? 11. What is the function of the following structures: A. Typhlosole B. Crop C. Gizzard D. Setae E. Proboscis F. Clitellum G. Aortic arches H. Nephridia I. Parapodia 12. Identify the 3 parts of the nervous system of annelids. 13. What does “annellus” mean? 14. Which is the largest class in phylum Annelida? 15. Why do Oligochaetes have a specialized digestive system? 16. How does sexual reproduction take place in earthworms? What 2 structures must line to ensure the successful delivery of sperm? 17. Explain how each class gets it’s name: A. Polychaeta B. Oligochaeta C. Hirudinea

6. REVIEW ANSWERS • 1. # of setae & presence or absence of parapodia • 2. provides more flexibility & greater reproductive opportunity • 3. diffusion • 4. metamerism-segmental arrangement of body parts in an animal • 1. creation of hydrostatic compartments which allow a variety of advantageous locomotor and supportive functions that would not be possible otherwise • 2. lessens the impact of injury—if one or a few segments are injured, adjacent segments set off by septa, may be able to maintain nearly normal functions which increase survival chances • 3. permits modification of certain regions of the body for specialized functions, such as feeding, locomotion, & reproduction • 5. tagmatization-the specialization of body regions in a metameric animal • 6. 1. Polychaeta==fireworm 2. Oligochaeta==earthworm 3. Hirudinea==leech • 7. posterior setae anchor circular muscles contract anterior setae anchprcircular muscles relax & longitudinal muscles contract • 8. mouthpharynxcropgizzardintestinesnutrients absorbed by blood w/ help of typhlosoleundigested material exits anus

7. 9. setae & parapodia • 10. to increase blood flow • 11. typhlosole- increase surface area for absorbtion • Crop-temporary storage • Gizzard-grind the food • Setae-locomotion & burrowing • Proboscis-sucking organ • Clitellum- makes eggs • Aortic arches-links dorsal and ventral blood vessels; hearts • Nephridia-excretory organ • Parapodia-paddle-like appendages where the bristles are located • 12. anterior nerve ring, ganglia, ventral nerve cord • 13. little rings • 14. Polychaeta • 15. to obtain the maximum amount of nutrients from the detritus • 16. cross fertilize by exchanging sperm—clitellum & testis must line up • 17. Polychaeta—many bristles Oligochaeta-few bristles Hirudinea—Hirudinis the anticoagulant in saliva • 18. in order for diffusion to take place for respiration • 19. mucus • 20. prostomium is the flap before the mouth of an earthworm; periostium-the segment containing the mouth • 21. nightcrawlers 22. anesthetic-numbs skin; anticoagulant-thins blood to prevent clotting • 23. because they have a natural anesthetic in their saliva (this is different from HIRUDIN=anticoagulant) • 24. they bring nutrients to surface of soil & break down organic matter • 25. Hirudomedicinalis 26. anterior=small=sucking blood; posterior-larger=attachment/locomotion